A conventional rotor for a claw-pole motor has been disclosed that generates N and S magnetic poles on the surfaces of first and second claw-pole magnetic bodies by using an annular permanent magnet that is magnetized in the axial direction (see, for example, Patent Literature 1).
Furthermore a conventional rotor for a hybrid stepping motor has been disclosed that consists of a cylindrical permanent magnet magnetized in the axial direction; two rotor magnetic bodies formed by stacking steel plates on both sides of the permanent magnet in the axial direction and fixed to hold the permanent magnet therebetween; and a shaft penetrating the permanent magnet and the rotor magnetic bodies (see, for example, Patent Literature 2).
Further, a conventional rotor for a permanent magnet motor has been disclosed that generates N and S magnetic poles on the surface of a magnetic body between permanent magnets by magnetizing permanent magnets between 2Z slots in the axial direction (see, for example, Patent Literature 3).
The techniques disclosed in Patent Literatures 1 to 3 described above all employ a rotor structure that causes magnetic fluxes generated by permanent magnets to flow in the axial direction so as to generate N and S magnetic poles on the surface of the rotor magnetic body. This structure causes magnetic fluxes of the stator to flow through the inside of the rotor magnetic body, which has a low magnetic resistance, instead of flowing through the permanent magnets. This structure can therefore reduce a reverse magnetic field to the permanent magnets, prevent demagnetization of the permanent magnets, and improve demagnetization resistance of the permanent magnets.